1989 tacoma bogging

Hey guys I want to buy this old tacoma because ive always wanted one, but it has a bogging issue. Aparently it boggs like it is leaning out, thats what the guy said whos selling it. Heres his description...

Hi im selling my 1989 toyota single cab shortbox 4x4 4cly 5spd 22re aisin locking hubsthe body is in rough shape mainly the box this is a great parts truck or project its still insured and is a one owner truck originally from dawson creek B.C it just started acting up 2 days ago it bogs out like its being starved for fuel when accelerating im going to replace the fuel filter this weekend but the converter pipe and catalytic need to be replaced so theres a good possibility that the problem is being caused by a faulty o2 sensor reading.the 22re engine has only 184608kms on it and if you have any clue about these engines you know they have no problem reaching 500 plus.the 4x4 in this truck is amazing and in my opinion it cant be beat.lots of new parts I just replaced the clutch ,front pads rotors and calipers break lines to the front , new rear shocks sensatrac all new air intake gaskets new radiator , thermostat and filters the head gasket was replaced and new head was installed.this truck has always been serviced according to dealer specifications.it has a nice professional custom made bush guard and custom made rear bumper the interior is in great shape.I had plans to completly rebuild this truck but i have a 4 year old and really need a bigger 4x4 with a back seat.

Could it really be an oxygen sensor or is the head gasket leaking? Do you think the truck is really worth it? Thanks guys.